Breaking News
More () »

What's the difference between PCR and rapid tests for detecting COVID-19?

Dr. Duke says people should take the rapid tests if they're symptomatic for more accurate results, and to take the PCR if you're asymptomatic or plan to travel.

MACON, Ga. — One Macon family is in quarantine after testing positive for COVID-19. They say this is a disappointment because their original tests came back negative. 

"I had a serious headache, back pain, nausea, stuffy nose, vomiting," Alonzo Culler said.

Those symptoms drove Culler to get a COVID-19 test immediately. 

"I got the rapid test from a new site. They gave us a negative result," Culler said.

After days of no improvement, Culler went to get a PCR test, which came back positive. 

Now, his whole household has the virus. 

"I want people to know their body. If you're sick and feeling something you've never felt before, do not rely on that rapid test, go get a second opinion," Culler said.

What is the difference between a PCR test and a rapid test?

For one, you receive the results from rapid tests within hours, and PCR test results may take a few days.

"Both are designed to detect the virus. The PCR, polymerase chain reaction, what that does is amplify the number of viral particles and it becomes an ultra-sensitive test," Dr. Sandy Duke with Atrium Health Navicent said.

Duke says the antigen, or "rapid" test, is not as sensitive and is not looked at in a lab. 

"If you're in the early phases of infection and the viral load is low, the rapid, or at-home test, may not be sensitive enough to pick up on that," Dr. Duke said.

Duke says other reasons for receiving a false result include sampling or timing problems. 

"As we're dealing with the Omicron variant right now, one of the frustrations that we've had and what we're seeing is that people can shed the virus a couple of days before they become symptomatic," Dr. Duke said.

He says this is why it's important to keep wearing your mask and social distancing, because there is a 24- to 48-hour window in which you may spread the virus and not know.